KR20070082967A - Damping force controlling valve and shock absorber of using the same - Google Patents

Abstract

A variable valve for a damping force and a shock absorber of using the same are provided to restrict a flow rate supplied to the second and third passages to slightly maintain the pressure of inlets of the first and second variable orifices, thereby restricting a leakage amount toward the second variable orifice under a high-speed condition in a soft mode. The first passage(Qm) couples a high-pressure side to a low pressure side by opening a valve. The second passage(Qr) is connected to the high-pressure side and the low pressure side by the first fixing orifice(Kr) and the first variable orifice(Kvr). The third passage(Qv) is connected to the high-pressure side and the low pressure side by opening the second variable orifice(Kcr) and the second fixing orifice(Kc). The third passage(Qv) controls the pressure of a pilot chamber according to the pressure of the second variable orifice(Kcr) and the second fixing orifice(Kc).

Description

DAMPING FORCE CONTROLLING VALVE AND SHOCK ABSORBER OF USING THE SAME

1 is a cross-sectional view showing a damping force variable valve of a shock absorber according to the prior art.

Figure 2 is a flow diagram briefly showing the flow path of the damping force variable valve according to the prior art.

3 is a cross-sectional view showing the structure of a shock absorber having a damping force variable valve according to the present invention.

4 to 6 is an operating state diagram of the damping force variable valve according to the present invention.

Figure 7 is a flow diagram briefly showing the flow path of the damping force variable valve according to the present invention.

<Explanation of symbols for main parts of the drawings>

50: shock absorber 52: cylinder

54: piston rod 55: piston valve

56: base shell 57: road guide

58: body valve 58: body valve

59a: upper cap 59b: base cap

60: tension chamber 62: compression chamber

64: reservoir chamber 68: intermediate tube

70: variable damping force valve 75: actuator

76: pressurized rod 80: spool rod

82: first ring disk 83: spring

84: lower retainer 85: spool

86: second ring disk 87: nut

88: upper retainer 89: bypass flow path

92: inlet chamber 95: pilot chamber

The present invention relates to a variable damping force valve and a shock absorber using the same, and more particularly, a damping force variable valve provided with an orifice at an inlet of a pilot flow path to have a high speed damping force when the shock absorber operates in a soft mode. It relates to the shock absorber used.

In general, the shock absorber of the vehicle is installed on the vehicle or the like and absorbs and cushions the shock generated by the friction with the road surface.

These shock absorbers lower the damping force during normal driving to absorb vibrations caused by the unevenness of the road surface, and improve ride comfort.In addition, the damping force is increased during turning, acceleration, braking, and high-speed driving to suppress the change of the body itself to improve steering stability. Can be.

On the other hand, the recent shock absorber is provided with a variable damping force variable valve capable of appropriately adjusting the damping force characteristics on one side, and the damping force variable type that can appropriately adjust the damping force characteristics for improving riding comfort and steering stability according to the road surface and driving conditions. It was developed as a shock absorber.

In general, conventional damping force variable shock absorbers control the damping force variable by the solenoid driving method, and the mainstream is classified into a reverse type or a normal type according to the damping force control method.

The damping force variable shock absorber described above is configured to simultaneously increase or simultaneously dampen the rebound damping force and the compression damping force according to the solenoid current. For example, the conventional damping force variable shock absorber controls the damping force on the rebound and compression side in soft mode by applying a predetermined solenoid current, and hardens the damping force on the rebound and compression side by applying a higher solenoid current. Control in mode Such damping force control is achieved by controlling the back pressure formation and regulation of the pilot chamber in which the spool moving in accordance with the solenoid drive is formed behind the damping force variable valve.

1 is a cross-sectional view showing a damping force variable valve of a shock absorber according to the prior art.

In the conventional damping force variable valve 10, as shown in FIG. 1, a spool rod 20 having a plurality of flow paths in which fluid is communicated is installed on an upper portion of the actuator 15, and the spool rod 20 is provided. The spool 25 is installed by the actuator 15 and opens and closes each flow path.

In addition, the spool rod 20 is provided with a first ring disk 32 serving as a fixed orifice in the spool rod 20, the upper portion of the lower portion including a connection port 34a to allow the flow of fluid Retainer 34 is installed.

In addition, a second ring disk 36 serving as a main valve is installed above the lower retainer 34. The second ring disk 36 partitions the pilot chamber 45 formed on the lower retainer 34 from the high pressure side Ph. In addition, an upper retainer 38 including a connection port 38a for allowing a fluid to flow is installed above the lower retainer 34.

A nut 27 is coupled to the spool rod 20 to bind the lower retainer 34 and the upper retainer 38. Meanwhile, a plug is installed at one end of the spool rod 20, and a spring 23 is interposed between the plug and the spool 25 to closely contact the spool 25 to the actuator 15.

The spool 25 has a hollow portion (not shown) and a plurality of stepped outer diameters in the vertical direction, among which an upper spool slit 25a and a lower spool slit 25b are formed in a stepped portion having a large outer diameter. . In this case, the upper spool slit 25a is formed larger than the lower spool slit 25b, and thus, when the spool 25 reciprocates, the connection port 21a of the spool rod 20 of the upper spool slit 25a , The area change rate for 21b, 21c becomes larger than the area change rate for the connection port of the spool rod 20 of the lower spool slit 25b.

FIG. 2 is a flow diagram schematically showing a flow path of the variable damping force valve 10 according to the prior art. Referring to the following, the operation of the variable damping force variable valve 10 according to the prior art configured as described above will be described below. Same as

As described above, the damping force variable valve 10 includes a first flow path Qm including a main valve Km, a second flow path Qr including a first variable orifice Kr, and a second variable flow. It consists of the 3rd flow path Qc containing the orifice Kv and the fixed orifice Kc.

The first variable orifice Kr has a larger area change ratio than the second variable orifice Kv and permits a flow rate from the high pressure side Ph to the low pressure side Pl, As the area increases, the area of the first variable orifice Kr decreases, and as the area of the second variable orifice Kv decreases, the area of the first variable orifice Kr increases.

The first flow path (Qm) determines the valve characteristics in the medium / high speed section of the soft / hard mode, has a spring preload in the form of a relief valve and the pilot chamber 45 is formed on the valve back to the valve opening pressure according to the pressure It is possible to vary the damping force by determining

In addition, the main valve Km opens at a different pressure according to the pressure Pc of the pilot chamber 45, and the pressure Pc of the pilot chamber 45 is a second variable installed upstream of the third flow path Qc. It is formed by the action of the orifice Kv and the fixed orifice Kc provided downstream. Therefore, by controlling the area of the second variable orifice Kv, the pressure in the pilot chamber 45 is increased to switch to the hard mode.

In this case, as the cross-sectional area of the first variable orifice Kr increases, the cross-sectional area of the second variable orifice Kv decreases, and as the cross-sectional area of the first variable orifice Kr decreases, the cross-sectional area of the first variable orifice Kr increases. Increases.

Further, the second flow path Qr determines the low speed damping force characteristic in the soft mode, and its area is converted by the first variable orifice Kr to determine the damping force.

The third flow path Qc is provided with a second variable orifice Kv at the inlet side and a fixed orifice Kc at the outlet side to form pressure in the pilot chamber 45.

When the damping force characteristic formed in such a structure is in the soft mode, the area of the first variable orifice Kr is increased to lower the low speed damping force, and at the same time, the flow path of the second variable orifice Kv is blocked, thereby blocking the pilot chamber 45. By lowering the pressure of the main valve (Km) is opened at a low pressure.

On the other hand, when the damping force characteristic is the hard mode, on the contrary, the first variable orifice Kr is closed and the second variable orifice Kv is opened to increase the opening pressure of the main valve Km to increase the damping force.

However, the damping force variable valve 10 according to the related art and the shock absorber using the same have a spool which forms the second variable orifice Kv when the pressure on the high pressure side Ph is increased under high speed conditions in the soft mode. Fluid is introduced into the pilot chamber 45 by the gap between the 25 and the spool rod 20, which causes a problem in that the pressure in the pilot chamber 45 is increased to increase the damping force characteristics.

The present invention is to solve the above-described problems of the prior art, the first and second variable orifice inlet side pressure to the high-pressure side pressure so that the amount of fluid supplied to the second flow path and the third flow path is first limited. In comparison, the damping force to the second variable orifice is limited in the high speed condition in the soft mode, so that the damping force variable valve and the shock absorber using the same are maintained. To provide.

In order to achieve the above object, the damping force variable valve according to the present invention has a cylinder and a reservoir chamber communicating with the cylinder, and the damping force variable valve having a high pressure side connected to the tension chamber of the cylinder and a low pressure side connected to the reservoir chamber is formed. A damping force variable valve installed in a business, comprising: a first flow path connecting the high pressure side and the low pressure side by opening a main valve provided between the high pressure side and the low pressure side, and a first fixed orifice connected to the high pressure side; And a first variable orifice connecting the first fixed orifice and the low pressure side to form a second flow path connected by opening of the first fixed orifice and the first variable orifice, and the first fixed orifice and the pilot chamber. A second variable orifice for connecting and a second fixed orifice for connecting the pilot chamber and the low pressure side are formed, and the second variable orifice And a third flow path connected by the opening of the second fixed orifice and controlling the pressure of the pilot chamber according to the pressure of the second variable orifice and the second fixed orifice.

In addition, the first variable orifice and the second variable orifice is opened and closed by a spool operated by one actuator, it is preferable that each orifice is controlled to vary in conjunction. In addition, the cross-sectional areas of the first variable orifice and the second variable orifice may be formed in inverse proportion to each other. In addition, the main valve may be formed of a disk-type membrane integrally formed.

In addition, in order to achieve the above object, the shock absorber according to the present invention has a high pressure side and a low pressure side of the above-mentioned damping force variable valve connected to the compression chamber and the reservoir chamber of the cylinder, respectively.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view showing the structure of a shock absorber having a damping force variable valve according to the present invention.

In the shock absorber 50 according to the present invention, as shown in FIG. 3, the lower end of the cylinder 52 having a predetermined length and diameter is connected to the axle, and the piston rod 54 is provided inside the cylinder 52. ) Is installed to be linearly movable.

Here, the cylinder 52 is filled with a working fluid such as gas or oil, and the base shell 56 is disposed outside the cylinder 52. On the other hand, the rod guide 57 and the body valve 58 is installed at the upper and lower ends of the cylinder 52 and the base shell 56, respectively, the space in the cylinder 52, the tension chamber 60 and the compression chamber A piston valve 55 partitioned by 62 is coupled to the lower end of the piston rod 54 so as to be reciprocated. In addition, an upper cap 59a and a base cap 59b are installed at upper and lower portions of the base shell 56, respectively.

In addition, a reservoir chamber 64 is formed between the cylinder 52 and the base shell 56 to compensate for a volume change inside the cylinder 52 according to the up and down movement of the piston rod 54. 64, the fluid flow with the compression chamber is controlled by the body valve (58).

On the other hand, the shock absorber 50 is provided with a variable damping force valve 70 for varying the damping force on one side of the base shell 56. In addition, the shock absorber 50 includes an intermediate tube 68 connected to the compression chamber 62 of the cylinder 52 between the cylinder 52 and the base shell 56, and the damping force. The variable valve 70 has a high pressure side Ph connected to the tension chamber 60 of the cylinder 52 and a low pressure side Pl connected to the reservoir chamber 64 through the intermediate tube 68. .

4 to 6 is an operation state diagram of the variable damping force valve according to the present invention, the structure of the damping force variable valve according to the present invention with reference to this as follows.

The above-described damping force variable valve 70 has a plurality of flow paths formed therein, and linearly moves in conjunction with the pressure rod 76 while being disposed on the same axis as the pressure rod 76 of the actuator 75. And a spool 85. The spool 85 is moved along the spool rod 80, one end of which is in contact with the pressure rod 76, the other end of which is elastically supported by the compression spring 83. Therefore, the spool 85 is advanced by the pressure of the pressure rod 76 and retracted by the restoring force of the compression spring 83.

In addition, the spool rod 80 has a hollow for inserting the spool 85 in the center, a plurality of connections for connecting the hollow of the spool rod 80 and the outside of the spool rod 80 in the radial direction Ports 81a, 81b, 81c are formed. In addition, the spool 85 has a plurality of stepped outer diameters in the vertical direction, among which the upper spool slit 85a is connected to the hollow of the spool rod 80 and the lower spool slit ( 85b) wherein the spool 85 is connected to the spool rod 80 such that the upper spool slit 85a or lower spool slit 85b is connected to the connection ports 81a, 81b, 81c. It connects and connects the internal flow path.

As such, one actuator 75 controlling the spool 85 is sufficient, and the spool 85 is connected to the actuator 75 to a connection port between the spool 85 and the spool rod 80. The first variable orifice (Kvr) and the second variable orifice (Kcr) formed by the interlocking control.

In addition, a first ring disk 82 is fitted to the spool rod 80, and a lower retainer 84 is coupled to the upper portion thereof to fix the first ring disk 82. In addition, the lower retainer 84 is formed at the lower side of the inlet chamber 92 controlled by the first ring disk 82, the upper chamber is formed with a pilot chamber 95, the inlet chamber 92 and Connection ports 84a are formed that allow the flow of fluid between the pilot chambers 95.

In this case, the first ring disk 82 serves as a main valve Km, and is integrally formed. The first ring disk 82 is preferably a membrane having a disk type. Accordingly, the main valve Km is opened by the first ring disk 82 according to the pressure of the high pressure side Ph, the initial preload and the pressure of the pilot chamber 95, and the fluid of the high pressure side Ph is opened. Allow to flow directly to the low pressure side (Pl).

In addition, a plurality of slits are formed in the circumferential portion of the first ring disk 82, and a second fixed orifice Kc through which the fluid of the pilot chamber 95 is fixedly discharged is formed.

In addition, a second ring disk 86 inserted into the spool rod 80 is disposed above the lower retainer 84, and the second ring disk 86 moves the pilot chamber 95 to a high pressure side ( Ph). In addition, a plurality of slits are formed on the inner circumference of the second ring disk 86 to form a first fixed orifice Kr through which the fluid introduced from the high pressure side Ph is discharged.

In addition, the spool rod 80 is coupled to the upper retainer 88, the connection port 88a is formed to allow the flow of the fluid is fixed to the second ring disk 86. The upper retainer 88 is formed with a bypass flow path 89 for connecting the inside of the hollow spool rod 80 to the low pressure side Pl.

On the other hand, the fluid flowing into the first fixed orifice (Kr) of the second ring disk 86 is connected to the spool rod 80 of the spool rod (80a, 81b, 81c) by the actuator (75) 85 is introduced into the first variable orifice Kvr or the second variable orifice Kcr. In this case, as the cross-sectional area of the first variable orifice Kvr increases, the cross-sectional area of the second variable orifice Kcr decreases, and as the cross-sectional area of the first variable orifice Kvr decreases, the second variable orifice Kcr Cross-sectional area increases.

A nut 87 is coupled to the spool rod 80 to bind the lower retainer 84 and the upper retainer 88.

Therefore, as shown in FIG. 4, when the spool 85 is retracted, the first fixed orifice Kr and the first variable orifice Kvr are connected. At this time, the fluid flowing from the high pressure side (Ph) is introduced into the spool rod 80 through the first fixed orifice (Kr), a connection port and the first variable orifice (Kvr), and then the bypass It is discharged to the low pressure side Pl through the flow path 89.

Meanwhile, as shown in FIG. 5, when the spool 85 is advanced, the first fixed orifice Kr and the first variable orifice Kvr are blocked. When the spool 85 is fully advanced, the first fixed orifice Kr and the second variable orifice Kcr are connected to each other. At this time, the fluid flowing from the high pressure side Ph is supplied to the lower spool slit 85b of the spool rod 80 through the first fixed orifice Kr, the connection port and the second variable orifice Kcr. . In addition, a part of the fluid introduced through the lower spool slit 85b is introduced into the pilot chamber 95 to increase the pressure of the first ring disk 82 to increase the pressure of the main valve Km. To control. In addition, the remainder of the fluid introduced through the lower spool slit 85b is discharged to the low pressure side Pl through the second fixed orifice Kc.

On the other hand, when the pressure of the fluid flowing into the high pressure side (Ph) is higher than the pressure of the pilot chamber 95, as shown in Figure 6, the first ring disk 82 is opened, the main valve (Km) is opened do. Therefore, the fluid flowing from the high pressure side Ph is discharged directly to the low pressure side Pl through the main valve Km, and high damping force is generated in this process.

7 is a flow diagram schematically showing the flow path of the variable damping force valve 70 according to the present invention, the operation of the variable damping force valve 70 according to the present invention configured as described above with reference to this Same as

In the damping force variable valve 70 according to the present invention, as shown in FIG. 7, three flow paths are formed to have different damping force characteristics by the fluid passing through each flow path. In this case, the three flow paths formed in the damping force variable valve 70 may include a first flow path Qm including a main valve Km, a first fixed orifice Kr and a first variable orifice Kvr. And a third flow path Qv including a second flow path Qr and a first fixed orifice Kr, a second variable orifice Kcr, and a second fixed orifice Kc.

The first flow path Qm is opened and closed by a main valve Km, and the main valve Km is an initial preload and pilot chamber formed by an operating pressure of the high pressure side Ph and a spring 83, etc. The opening and closing is controlled according to the pressure of 95).

In addition, the fluid flowing from the high pressure side Ph is supplied through the first fixed orifice Kr, and the second flow path Qr or the third flow path Qv formed as the spool 85 moves forward or backward. Is supplied.

The second flow path Qr further includes a first fixed orifice Kr connected to the high pressure side Ph, and a first variable orifice Kvr connecting the first fixed orifice and the low pressure side Pl. After the flow path supplied through the first fixed orifice Kr flows into the first variable orifice Kvr, it is discharged to the low pressure side Pl through the bypass flow path 89.

In addition, the third passage Qv connects the second variable orifice Kcr connecting the first fixed orifice Kr and the pilot chamber 95 to the pilot chamber 95 and the low pressure side Pl. The second fixed orifice Kc is formed. In addition, the third flow path Qv is connected by the opening of the second variable orifice Kcr and the second fixed orifice Kc, and a part of the flow path supplied to the third flow path Qv is a pilot chamber ( 95) to control the opening and closing of the main valve (Km). In this case, when there is a lot of fluid supplied through the second variable orifice Kcr, when the amount of fluid supplied to the pilot chamber 95 increases, the pressure of the main valve Km is increased so as to increase the first flow path Qm. Reduce the amount of fluid passing through it. On the other hand, when the amount of fluid supplied through the second variable orifice Kcr is small, when the amount of fluid supplied to the pilot chamber 95 decreases, the pressure of the main valve Km decreases to open the first flow path Qm. The amount of fluid passing through will increase.

Therefore, the first fixed orifice Kr is installed at the inlet of the first variable orifice Kvr and the second variable orifice Kcr to adjust the amount of fluid supplied to the second flow path Qr and the third flow path Qc. Primary control

When the damping force characteristic formed in such a structure is in the soft mode, the area of the first variable orifice Kvr is increased to lower the low speed damping force, and at the same time, the flow path of the second variable orifice Kcr is blocked to block the pilot chamber 45. By lowering the pressure of the main valve (Km) is opened at a low pressure.

On the other hand, when the damping force characteristic is in hard mode, on the contrary, the first variable orifice Kvr is closed and the second variable orifice Kcr is opened to increase the opening pressure of the main valve Km to increase the damping force.

On the other hand, in such a structure, when the area of the first variable orifice Kvr is set to be larger than the area of the first fixed orifice Kr in soft mode conditions, the inlet of the first variable orifice Kvr and the second variable orifice Kcr The pressure on the side can be kept relatively small compared to the high pressure (Ph) pressure. This allows low damping force characteristics at high speeds in soft mode.

As described above, the damping force variable valve and the shock absorber using the same according to the present invention have been described with reference to the illustrated drawings, but the present invention is not limited to the embodiments and drawings described above, and the present invention within the claims. Of course, various modifications and variations can be made by those skilled in the art.

The damping force variable valve and the shock absorber using the same according to the present invention configured as described above allow the amount of fluid supplied to the second flow path and the third flow path to be primarily limited, thereby reducing the pressure at the inlet side of the first and second variable orifices. Compared to the high pressure side pressure can be kept relatively small, through which the amount of leakage to the second variable orifice side in the high speed condition in the soft mode is limited, there is an advantage that can maintain the damping force characteristics at high speed.

Claims (5)

A damping force variable valve having a cylinder and a reservoir chamber communicating with the cylinder, the damping force variable valve being installed in a damping force variable shock shop having a high pressure side connected to the tension chamber of the cylinder and a low pressure side connected to the reservoir chamber, A first flow passage connecting the high pressure side and the low pressure side by opening of a main valve provided between the high pressure side and the low pressure side; A first fixed orifice connected to the high pressure side, a first variable orifice connecting the first fixed orifice and the low pressure side, and a second flow path connected by opening of the first fixed orifice and the first variable orifice; , A second variable orifice connecting the first fixed orifice and a pilot chamber, and a second fixed orifice connecting the pilot chamber and the low pressure side are formed, and are connected by the opening of the second variable orifice and the second fixed orifice. And a third flow path for controlling the pressure of the pilot chamber according to the pressures of the second variable orifice and the second fixed orifice. The method according to claim 1, And the first variable orifice and the second variable orifice are opened and closed by a spool operated by one actuator, and each orifice is controlled to work in conjunction with each other. The method according to claim 1 or 2, And a cross-sectional area of the first variable orifice and the second variable orifice is inversely proportional to each other. The method according to claim 1 or 2, The main valve is a variable damping force valve, characterized in that formed of a disk-type membrane made in one piece. A shock absorber, characterized in that the high pressure side and the low pressure side of the damping force variable valve according to claim 1 or 2 are connected to the compression chamber and the reservoir chamber of the cylinder, respectively.

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